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1.
J Am Chem Soc ; 2024 May 28.
Article in English | MEDLINE | ID: mdl-38805725

ABSTRACT

Cu-based catalysts are optimal for the electroreduction of CO2 to generate hydrocarbon products. However, controlling product distribution remains a challenging topic. The theoretical investigations have revealed that the coordination number (CN) of Cu considerably influences the adsorption energy of *CO intermediates, thereby affecting the reaction pathway. Cu catalysts with different CNs were fabricated by reducing CuO precursors via cyclic voltammetry (Cyc-Cu), potentiostatic electrolysis (Pot-Cu), and pulsed electrolysis (Pul-Cu), respectively. High-CN Cu catalysts predominantly generate C2+ products, while low-CN Cu favors CH4 production. For instance, over the high-CN Pot-Cu, C2+ is the main product, with the Faradaic efficiency (FE) reaching 82.5% and a partial current density (j) of 514.3 mA cm-2. Conversely, the low-CN Pul(3)-Cu favors the production of CH4, achieving the highest FECH4 value of 56.7% with a jCH4 value of 234.4 mA cm-2. In situ X-ray absorption spectroscopy and Raman spectroscopy studies further confirm the different *CO adsorptions over Cu catalysts with different CN, thereby directing the reaction pathway of the CO2RR.

2.
J Med Chem ; 67(8): 6456-6494, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38574366

ABSTRACT

Dysregulation of IL17A drives numerous inflammatory and autoimmune disorders with inhibition of IL17A using antibodies proven as an effective treatment. Oral anti-IL17 therapies are an attractive alternative option, and several preclinical small molecule IL17 inhibitors have previously been described. Herein, we report the discovery of a novel class of small molecule IL17A inhibitors, identified via a DNA-encoded chemical library screen, and their subsequent optimization to provide in vivo efficacious inhibitors. These new protein-protein interaction (PPI) inhibitors bind in a previously undescribed mode in the IL17A protein with two copies binding symmetrically to the central cavities of the IL17A homodimer.


Subject(s)
DNA , Drug Discovery , Interleukin-17 , Small Molecule Libraries , Interleukin-17/metabolism , Interleukin-17/antagonists & inhibitors , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology , DNA/metabolism , DNA/chemistry , Humans , Animals , Structure-Activity Relationship , Protein Binding , Mice
3.
Angew Chem Int Ed Engl ; 63(15): e202400439, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38345401

ABSTRACT

Electroreduction of CO2 to C2+ products provides a promising strategy for reaching the goal of carbon neutrality. However, achieving high selectivity of C2+ products at high current density remains a challenge. In this work, we designed and prepared a multi-sites catalyst, in which Pd was atomically dispersed in Cu (Pd-Cu). It was found that the Pd-Cu catalyst had excellent performance for producing C2+ products from CO2 electroreduction. The Faradaic efficiency (FE) of C2+ products could be maintained at approximately 80.8 %, even at a high current density of 0.8 A cm-2 for at least 20 hours. In addition, the FE of C2+ products was above 70 % at 1.4 A cm-2. Experiments and density functional theory (DFT) calculations revealed that the catalyst had three distinct catalytic sites. These three active sites allowed for efficient conversion of CO2, water dissociation, and CO conversion, ultimately leading to high yields of C2+ products.

4.
Nat Commun ; 15(1): 1109, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38321049

ABSTRACT

Upcycling of CO2 into fuels by virtually unlimited solar energy provides an ultimate solution for addressing the substantial challenges of energy crisis and climate change. In this work, we report an efficient nanostructured Ru/MnOx catalyst composed of well-defined Ru/MnO/Mn3O4 for photo-thermal catalytic CO2 hydrogenation to CH4, which is the result of a combination of external heating and irradiation. Remarkably, under relatively mild conditions of 200 °C, a considerable CH4 production rate of 166.7 mmol g-1 h-1 was achieved with a superior selectivity of 99.5% at CO2 conversion of 66.8%. The correlative spectroscopic and theoretical investigations suggest that the yield of CH4 is enhanced by coordinating photon energy with thermal energy to reduce the activation energy of reaction and promote formation of key intermediate COOH* species over the catalyst. This work opens up a new strategy for CO2 hydrogenation toward CH4.

5.
Angew Chem Int Ed Engl ; 63(2): e202313796, 2024 Jan 08.
Article in English | MEDLINE | ID: mdl-38015565

ABSTRACT

Modulation of the microenvironment on the electrode surface is one of the effective means to improve the efficiency of electrocatalytic carbon dioxide reduction (eCO2 RR). To achieve high conversion rates, the phase boundary at the electrode surface should be finely controlled to overcome the limitation of CO2 solubility in the aqueous electrolyte. Herein, we developed a simple and efficient method to structure electrocatalyst with a superhydrophobic surface microenvironment by one-step co-electrodeposition of Cu and polytetrafluoroethylene (PTFE) on carbon paper. The super-hydrophobic Cu-based electrode displayed a high ethylene (C2 H4 ) selectivity with a Faraday efficiency (FE) of 67.3 % at -1.25 V vs. reversible hydrogen electrode (RHE) in an H-type cell, which is 2.5 times higher than a regular Cu electrode without PTFE. By using PTFE as a surface modifier, the activity of eCO2 RR is enhanced and water (proton) adsorption is inhibited. This strategy has the potential to be applied to other gas-conversion electrocatalysts.

6.
Mol Cell Biochem ; 479(3): 553-566, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37120495

ABSTRACT

Long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been shown to be a regulator for many cancers, including non-small cell lung cancer (NSCLC). Therefore, its role and mechanism in the process of NSCLC deserve to be further revealed. The expression levels of GAS5, fat mass and obesity-associated protein (FTO) and bromodomain-containing protein 4 (BRD4) were detected by quantitative real-time PCR. Western blot analysis was used to examine the protein expression of FTO, BRD4, up-frameshift protein 1 (UPF1) and autophagy-related markers. Methylated RNA immunoprecipitation was used to assess the m6A level of GAS5 regulated by FTO. Cell proliferation and apoptosis were determined using MTT assay, EdU assay and flow cytometry. Autophagy ability was assessed by immunofluorescence staining and transmission electron microscope. Xenograft tumor model was constructed to explore the effects of FTO and GAS5 on NSCLC tumor growth in vivo. The interaction between UPF1 and GAS5 or BRD4 was confirmed by pull-down assay, RIP assay, dual-luciferase reporter assay, and chromatin immunoprecipitation. Fluorescent in situ hybridization was used to analyze the co-localization of GAS5 and UPF1. Actinomycin D treatment was employed to evaluate BRD4 mRNA stability. GAS5 was downregulated in NSCLC tissues and was associated with poor prognosis in NSCLC patients. FTO was highly expressed in NSCLC, and it inhibited GAS5 expression by reducing GAS5 m6A methylation level. GAS5 suppressed by FTO could promote the autophagic death of NSCLC cells in vitro and inhibit NSCLC tumor growth in vivo. In addition, GAS5 was able to interact with UPF1 to reduce the mRNA stability of BRD4. Knockdown of BRD4 reversed the inhibition of GAS5 or UPF1 silencing on the autophagic cell death of NSCLC. The findings of the study showed that lncRNA GAS5 mediated by FTO could contribute to the autophagic cell death of NSCLC by interacting with UPF1 to reduce BRD4 mRNA stability, suggesting that GAS5 might be a vital therapy target for NSCLC progression.


Subject(s)
Autophagic Cell Death , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , MicroRNAs , RNA, Long Noncoding , Animals , Humans , Adenine/analogs & derivatives , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism , Autophagic Cell Death/genetics , Bromodomain Containing Proteins/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Cycle Proteins , Cell Proliferation/genetics , Demethylation , Disease Models, Animal , In Situ Hybridization, Fluorescence , Lung Neoplasms/genetics , Lung Neoplasms/pathology , MicroRNAs/genetics , Nuclear Proteins/metabolism , RNA Helicases/metabolism , RNA, Long Noncoding/metabolism , Trans-Activators/genetics , Trans-Activators/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
7.
Adv Mater ; 36(11): e2310273, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37974514

ABSTRACT

Cu2+ -based materials, a class of promising catalysts for the electrocatalytic carbon dioxide reduction reaction (CO2 RR) to value-added chemicals, usually undergo inevitable and uncontrollable reorganization processes during the reaction, resulting in catalyst deactivation or the new active sites formation and bringing great challenges to exploring their structure-performance relationships. Herein, a facile strategy is reported for constructing Cu2+ and 3, 4-ethylenedioxythiophene (EDOT) coordination to stabilize Cu2+ ions to prepare a novel layered coordination polymer (CuPEDOT). CuPEDOT enables selective reduction of CO2 to CH4 with 62.7% Faradaic efficiency at the current density of 354 mA cm-2 in a flow cell, and the catalyst is stable for at least 15 h. In situ spectroscopic characterization and theoretical calculations reveal that CuPEDOT catalyst can maintain the Cu2+ -EDOT coordination structurally stable in CO2 RR and significantly promote the further hydrogenation of *CO intermediates, favoring the formation of CH4 instead of dimerization to C2 products. The strong coordination between EDOT and Cu2+ prevents the reduction of Cu2+ ions during CO2 RR. The finding of this work provides a new perspective on designing molecularly stable, highly active catalysts for CO2 RR.

8.
Chem Sci ; 14(48): 14308-14315, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38098726

ABSTRACT

The electrochemical reduction of carbon dioxide (CO2RR) holds great promise for sustainable energy utilization and combating global warming. However, progress has been impeded by challenges in developing stable electrocatalysts that can steer the reaction toward specific products. This study proposes a carbon shell coating protection strategy by an efficient and straightforward approach to prevent electrocatalyst reconstruction during the CO2RR. Utilizing a copper-based metal-organic framework as the precursor for the carbon shell, we synthesized carbon shell-coated electrocatalysts, denoted as Cu-x-y, through calcination in an N2 atmosphere (where x and y represent different calcination temperatures and atmospheres: N2, H2, and NH3). It was found that the faradaic efficiency of ethanol over the catalysts with a carbon shell could reach ∼67.8%. In addition, the catalyst could be stably used for more than 16 h, surpassing the performance of Cu-600-H2 and Cu-600-NH3. Control experiments and theoretical calculations revealed that the carbon shell and Cu-C bonds played a pivotal role in stabilizing the catalyst, tuning the electron environment around Cu atoms, and promoting the formation and coupling process of CO*, ultimately favoring the reaction pathway leading to ethanol formation. This carbon shell coating strategy is valuable for developing highly efficient and selective electrocatalysts for the CO2RR.

9.
Chem Sci ; 14(41): 11474-11480, 2023 Oct 25.
Article in English | MEDLINE | ID: mdl-37886083

ABSTRACT

The construction of metal hetero-interfaces has great potential in the application of electro-catalytic carbon dioxide reduction (ECR). Herein, we report a fast, efficient, and simple electrodeposition strategy for synthesizing three-dimensional (3D) porous Cu/Zn heterostructures using the hydrogen bubble template method. When the deposition was carried out at -1.0 A for 30 s, the obtained 3D porous Cu/Zn heterostructures on carbon paper (CP) demonstrated a nearly 100% CO faradaic efficiency (FE) with a high partial current density of 91.8 mA cm-2 at -2.1 V vs. Ag/Ag+ in the mixed electrolyte of ionic liquids/acetonitrile in an H-type cell. In particular, the partial current density of CO could reach 165.5 mA cm-2 and the FE of CO could remain as high as 94.3% at -2.5 V vs. Ag/Ag+. The current density is much higher than most reported to date in an H-type cell (Table S1). Experimental and density functional theory (DFT) calculations reveal that the outstanding electrocatalytic performance of the electrode can be ascribed to the formation of 3D porous Cu/Zn heterostructures, in which the porous and self-supported architecture facilitates diffusion and the Cu/Zn heterostructures can reduce the energy barrier for ECR to CO.

10.
Org Lett ; 25(38): 6959-6963, 2023 Sep 29.
Article in English | MEDLINE | ID: mdl-37726896

ABSTRACT

The cross-coupling of epoxides with acyl chlorides or anhydrides by a nickel/titanocene dual catalytic system is established. A variety of synthetically useful ß-hydroxy ketones were obtained in good to high yields by using modified pyridine-oxazoline ligand. The reaction proceeds via the cooperation of titanocene-catalyzed ring-opening of epoxides and nickel-catalyzed acylation of the benzylic radical intermediate.

11.
J Am Chem Soc ; 145(31): 17253-17264, 2023 Aug 09.
Article in English | MEDLINE | ID: mdl-37498730

ABSTRACT

The electrochemical CO2 reduction reaction (CO2RR) using renewable electricity is one of the most promising strategies for reaching the goal of carbon neutrality. Multicarbonous (C2+) products have broad applications, and ethanol is a valuable chemical and fuel. Many Cu-based catalysts have been reported to be efficient for the electrocatalytic CO2RR to C2+ products, but they generally offer limited selectivity and current density toward ethanol. Herein, we proposed a silica-mediated hydrogen-bonded organic framework (HOF)-templated approach to preparing ultrahigh-density Cu single-atom catalysts (SACs) on thin-walled N-doped carbon nanotubes (TWN). The content of Cu in the catalysts prepared by this method could be up to 13.35 wt %. It was found that the catalysts showed outstanding performance for the electrochemical CO2RR to ethanol, and the Faradaic efficiency (FE) of ethanol increased with the increase in Cu-N3 site density. The FE of ethanol over the catalysts with 13.35 wt % Cu could reach ∼81.9% with a partial current density of 35.6 mA cm-2 using an H-type cell, which is the best result for electrochemical CO2RR to ethanol to date. In addition, the catalyst could be stably used for more than 25 h. Experimental and density functional theory (DFT) studies revealed that the adjacent Cu-N3 active sites (one Cu atom coordinates with three N) were the active sites for the reaction, and their high density was crucial for the high FE of ethanol because the adjacent Cu-N3 sites with a short distance could promote the C-C coupling synergistically.

12.
ChemSusChem ; 16(19): e202300807, 2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37366066

ABSTRACT

A parallel paired electrosynthetic method, coupling electrocarboxylation incorporating CO2 into ketone, imine, and alkene with alcohol oxidation or oxidative cyanation of amine, was developed for the first time. Various carboxylic acids as well as aldehyde/ketone or α-nitrile amine were prepared at the cathode and anode respectively in a divided cell. Its utility and merits on simultaneously achieving high atom-economic CO2 utilization, elevated faradaic efficiency (FE, total FE of up to 166 %), and broad substrate scope were demonstrated. The preparation of pharmaceutical intermediates for Naproxen and Ibuprofen via this approach proved its potential application in green organic electrosynthesis.

13.
J Am Chem Soc ; 145(21): 11512-11517, 2023 May 31.
Article in English | MEDLINE | ID: mdl-37196054

ABSTRACT

Using bulk metals as catalysts to get high efficiency in electro-reduction of CO2 is ideal but challenging. Here, we report the coupling of bulk metal electrodes and a ternary ionic-liquid-based electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate/1-dodecyl-3-methylimidazolium tetrafluoroborate/MeCN to realize highly efficient electro-reduction of CO2 to CO. Over various bulk metal electrodes, the ternary electrolyte not only increases the current density but also suppresses the hydrogen evolution reaction to obtain a high Faradaic efficiency (FE) toward CO. FECO could maintain ∼100% over a wide potential range, and metal electrodes showed very high stability in the ternary electrolyte. It is demonstrated that the aggregation behavior of the ternary electrolyte and the arrangement of two kinds of IL cations with different chain lengths in the electrochemical double layer not only increase the wettability to electrode and CO2 adsorption but also extend the diffusion channel of H+, rendering the high current density and FECO.

14.
Front Plant Sci ; 14: 1140596, 2023.
Article in English | MEDLINE | ID: mdl-36968373

ABSTRACT

Chrysanthemum White Rust (CWR) caused by Puccinia horiana Henn. is a major disease in the production process of chrysanthemum, which is widely spread all over the world and can be called "cancer" of chrysanthemum. To clarify the disease resistance function of disease resistance genes can provide a theoretical basis for the utilization and genetic improvement of chrysanthemum resistant varieties. In this study, the resistant cultivar 'China Red' was used as the experimental material. We constructed the silencing vector pTRV2-CmWRKY15-1 and obtained the silenced line named TRV-CmWRKY15-1. The results of enzyme activity after inoculation with pathogenic fungi showed that the activities of antioxidant enzymes SOD, POD, CAT and defense-related enzymes PAL and CHI in leaves were stimulated under the stress of P. horiana. In the WT, the activities of SOD, POD and CAT at the peak value were 1.99 times, 2.84 times and 1.39 times higher than that in TRV-CmWRKY15-1, respectively. And the activities of PALand CHI at the peak were 1.63 times and 1.12 times of TRV-CmWRKY15-1. The content of MDA and soluble sugar also confirmed that chrysanthemum was more susceptible to pathogenic fungi when CmWRKY15-1 was silenced. The expression levels of POD, SOD, PAL and CHI at different time points showed that the expressions of defense enzyme related genes were inhibited in TRV-WRKY15-1 under the infection of P. horiana, which weakened the ability of chrysanthemum to resist white rust. In conclusion, CmWRKY15-1 may increased the resistance of chrysanthemum to white rust by increasing the activity of protective enzyme system, which laid a foundation for breeding new varieties with disease resistance.

15.
J Gene Med ; 25(5): e3479, 2023 05.
Article in English | MEDLINE | ID: mdl-36750649

ABSTRACT

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a worldwide public health problem. Previous genetic association studies have identified several susceptibility loci in the interleukin genes that may participate in the nosogenesis of COPD. This study aimed to evaluate the relationship between IL23R loci and COPD susceptibility in the Chinese population. METHODS: Agena MassARRAY technology was applied to genotype five single nucleotide polymorphisms (SNPs) in the IL23R gene in 498 COPD patients and 498 healthy people. The association between IL23R SNPs and COPD risk was calculated by logistic regression analysis, with odds ratios and 95% confidence intervals. The false-positive report probability analysis was noteworthy for evaluating the significant results. Also, haplotype analysis was performed among IL23R variants, and multifactor dimensionality reduction analysis was performed to assess the SNP-SNP interactions to predict the risk of COPD. RESULTS: Overall analysis showed that rs7517847 had a significant association with an increased risk of COPD. Age-stratified analysis revealed that rs7517847 was significantly related to an increased risk of COPD in people aged over 68 years old. Sex-stratified analysis illustrated a significant association between rs2295359 and rs7517847 and COPD risk in the female population. The significant association of COPD risk with IL23R SNPs was assessed by false-positive report probability values. Additionally, we observed that the haplotypes AAC and GGA formed by rs2201841, rs12743974 and rs10889677 were associated with a reduced risk of COPD (p = 0.009, p = 0.026). Also, the five-loci interaction model formed by rs2295359, rs7517847, rs2201841, rs12743974 and rs10889677 became the best predictor of COPD, with 10/10 cross-validation consistency and 52.4% testing balance accuracy. CONCLUSION: The research indicated a remarkable association between IL23R variants and COPD susceptibility in the Chinese population. Larger samples and functional research are required to ascertain the relationship between IL23R variants and COPD susceptibility.


Subject(s)
Genetic Predisposition to Disease , Pulmonary Disease, Chronic Obstructive , Humans , Female , Aged , East Asian People , Pulmonary Disease, Chronic Obstructive/genetics , Genotype , Asian People , Receptors, Interleukin/genetics
16.
J Biomol NMR ; 77(1-2): 39-53, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36512150

ABSTRACT

Fragment-based drug discovery (FBDD) and validation of small molecule binders using NMR spectroscopy is an established and widely used method in the early stages of drug discovery. Starting from a library of small compounds, ligand- or protein-observed NMR methods are employed to detect binders, typically weak, that become the starting points for structure-activity relationships (SAR) by NMR. Unlike the more frequently used ligand-observed 1D NMR techniques, protein-observed 2D 1H-15N or 1H-13C heteronuclear correlation (HSQC or HMQC) methods offer insights that include the mechanism of ligand engagement on the target and direct binding affinity measurements in addition to routine screening. We hereby present the development of a set of software tools within the MestReNova (Mnova) package for analyzing 2D NMR for FBDD and hit validation purposes. The package covers three main tasks: (1) unsupervised profiling of raw data to identify outlier data points to exclude in subsequent analyses; (2) batch processing of single-point spectra to identify and rank binders based on chemical shift perturbations or spectral peak intensity changes; and (3) batch processing of multiple titration series to derive binding affinities (KD) by tracing the changes in peak locations or measuring global spectral changes. Toward this end, we implemented and evaluated a set of algorithms for automated peak tracing, spectral binning, and variance analysis by PCA, and a new tool for spectral data intensity comparison using ECHOS. The accuracy and speed of the tools are demonstrated on 2D NMR binding data collected on ligands used in the development of potential inhibitors of the anti-apoptotic MCL-1 protein.


Subject(s)
Algorithms , Magnetic Resonance Imaging , Ligands , Nuclear Magnetic Resonance, Biomolecular , Drug Discovery
17.
J Am Chem Soc ; 144(45): 20834-20846, 2022 Nov 16.
Article in English | MEDLINE | ID: mdl-36332192

ABSTRACT

Cyclohexanols are widely used chemicals, which are mainly produced by oxidation of fossil feedstocks. Selective hydrodeoxygenation of lignin derivatives has great potential for producing these chemicals but is challenging to obtain high yields. Here, we report that CeO2-supported Ru single-atom catalysts (SACs) enabled the hydrogenation of the benzene ring and catalyzed etheric C-O(R) bond cleavage without changing the C-O(H) bond, which could afford 99.9% yields of cyclohexanols. As far as we know, this is the first to report that SACs catalyze hydrogenation of the aromatic ring. The reaction mechanism was studied by control experiments and density functional theory calculations. In the catalysts, the Ru-O-Ce sites were formed and one Ru atom was coordinated with about four O atoms. These catalytic sites could realize both the hydrogenation and deoxygenation reactions efficiently, and thus desired cyclohexanols were generated. This work pioneers the single-atom catalysis in aromatic transformation and provides a novel route for synthesis of cyclohexanols.

18.
Chron Respir Dis ; 19: 14799731221133389, 2022.
Article in English | MEDLINE | ID: mdl-36206158

ABSTRACT

OBJECTIVE: We aimed to explore the safety and diagnostic value of medical thoracoscopic lung biopsy in patients with unexplained diffuse interstitial lung disease (ILD) in a single center pilot study. METHOD: We retrospectively analyzed clinical and pathological diagnostic data from 52 patients with diffuse ILD undergoing medical thoracoscopic lung biopsy. RESULTS: Forty-four cases of diffuse ILD were confirmed pathologically, giving a diagnostic rate of 84.6%. Among these 44 patients, 11 patients were diagnosed with cancer, including eight patients with lung adenocarcinoma, three patients with metastases; two from a gastrointestinal malignancy, and one from a granulosa cell tumor of the ovary. There were 17 cases of idiopathic interstitial pneumonia, including nine cases of usual interstitial pneumonia (UIP), four cases of non-specific interstitial pneumonia (NSIP), three cases of cryptogenic organizing pneumonia (COP), and one case of acute interstitial pneumonia (AIP). There were 12 cases of rare interstitial pneumonias, which included six cases of pulmonary alveolar proteinosis, one case each of pulmonary Langerhans cell histiocytosis (LCH) and pulmonary lymphangiomyomatosis, two cases of nodular sarcoidosis, and two cases of chronic eosinophilic pneumonia. We recorded various complications, including bleeding, infection, and pneumothorax. A total of 28 patients (53.8%) experienced at least one of the above complications, but there were no deaths associated with biopsy. CONCLUSIONS: Medical thoracoscopic lung biopsy appears a safe and effective method for diagnosing diffuse ILD of unknown cause but further prospective studies, with larger numbers, including comparison with other established techniques are required.


Subject(s)
Idiopathic Interstitial Pneumonias , Lung Diseases, Interstitial , Anesthesia, Local , Biopsy/methods , Female , Humans , Idiopathic Interstitial Pneumonias/diagnosis , Lung/pathology , Lung Diseases, Interstitial/diagnosis , Pilot Projects , Prospective Studies , Retrospective Studies , Thoracoscopy/adverse effects
19.
J Am Chem Soc ; 144(42): 19627-19634, 2022 10 26.
Article in English | MEDLINE | ID: mdl-36254467

ABSTRACT

Asymmetric cycloaddition reactions are the most powerful tool to the expeditious construction of enantioenriched cyclic motifs in organic chemistry. In sharp contrast to well-developed cycloaddition reactions via the palladium-trimethylenemethane (Pd-TMM) intermediate, hetero (3 + 2) cycloadditions of the heteroallyl cations remain rare, largely due to their thermally forbidden nature. To the best of our knowledge, there is no example of asymmetric version leading to enantioenriched heterocycles reported so far. Herein we enabled the first example of catalytic asymmetric (3 + 2) cycloaddition of electrophilic palladium-heteroallyl zwitterion intermediate (Pd-OTMM or Pd-NTMM) with cyclic or acyclic 1,3-dienes via a pathway terminated with C-N or C-O bond formation, delivering the highly substituted or fused pyrrolidine and tetrahydrofuran rings in high yields with excellent regio-, diastereo-, and enantioselectivity. Engineering the PC-Phos, one of the chiral sulfinamide phosphine (Sadphos) type ligands, by introducing the di-tert-butyl or/and 3,5-difluorophenyl group is a vital component in achieving excellent catalytic reactivity and enantioselectivity.


Subject(s)
Palladium , Pyrrolidines , Palladium/chemistry , Cycloaddition Reaction , Stereoisomerism , Pyrrolidines/chemistry , Furans
20.
Chem Sci ; 13(31): 9047-9055, 2022 Aug 10.
Article in English | MEDLINE | ID: mdl-36091204

ABSTRACT

Low-temperature and selective reductive amination of carbonyl compounds is a highly promising approach to access primary amines. However, it remains a great challenge to conduct this attractive route efficiently over earth-abundant metal-based catalysts. Herein, we designed several Co-based catalysts (denoted as Co@C-N(x), where x represents the pyrolysis temperature) by the pyrolysis of the metal-organic framework ZIF-67 at different temperatures. Very interestingly, the prepared Co@C-N(800) could efficiently catalyze the reductive amination of various aldehydes/ketones to synthesize the corresponding primary amines with high yields at 35 °C. Besides non-noble metal and mild temperature, the other unique advantage of the catalyst was that the substrates with different reduction-sensitive groups could be converted into primary amines selectively because the Co-based catalyst was not active for these groups at low temperature. Systematic analysis revealed that the catalyst was composed of graphene encapsulated Co nanoparticles and atomically dispersed Co-N x sites. The Co particles promoted the hydrogenation step, while the Co-N x sites acted as acidic sites to activate the intermediate (Schiff base). The synergistic effect of metallic Co particles and Co-N x sites is crucial for the excellent performance of the catalyst Co@C-N(800). To the best of our knowledge, this is the first study on efficient synthesis of primary amines via reductive amination of carbonyl compounds over earth-abundant metal-based catalysts at low temperature (35 °C).

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